Nut fruits , also called nuts , are closing fruits in which all three layers of the pericarp (i.e. the pericarp ) lignify . Usually only a single seed , also known colloquially as a nut, is enclosed in the nutshell .
Shell fruits (also nuts ) is the common name for fruit whose kernels are surrounded by a hard, mostly woody shell . These are nuts and kernels that are suitable for human consumption. On the other hand, their pericarp - the peel or pericarp - is not suitable for consumption.
The word nut (from Middle High German nuz ), like the English nut, goes back to a primitive Germanic noun that can be reconstructed as * χnut- . This in turn continues a Urindo-European noun * knud- . The Celtic word * knūs , from which the Old Irish cnú and the Kymrian kneuen go back, and the Latin nux (nucis , f .; root word nuc-) , if derived from converted * dnuk- , all with the same meaning “nut” probably also set * knud- on.
Nuts in the botanical sense
The nuts in the botanical sense include u. a.
- Chilean hazelnut
- Real walnut ( Juglans regia ), until recently it was considered a stone fruit .
- Sweet Chestnut (Maroni)
- Peanut ( Arachis hypogaea ): As a legume , the fruit of the peanut is a derivative of the legume ; However, it remains closed (legume is an opening fruit) and therefore belongs to the nuts.
- Hemp nut
- Macadamia Nut (Queensland Nut)
- Sycamore nut (inedible)
- Corozo (Tagua)
- Water nut
Special forms of the nut fruit
- Wing fruit (pseudosamara) as in the hornbeam or the Virginian hop beech ( Ostrya virginiana ), the nut here is enveloped on one side or entirely in a wing-like bract (cover sheet, cover sheet).
- Tryma with a surrounding, open fruit cover like the hickory ( Carya spp.), Also species of the walnut family (Juglandaceae) can be included.
- Achenes of the composites , e.g. B. the fruits of the sunflower and the dandelion , but also the rose plants strawberry and the rose hip belong to it. They are not quite correctly referred to as common nut fruit , because it is actually a common achenecetum fruit.
- Caryopsis ; nut-like closing fruits of the grasses
- Wingnut (samara); nut-like with a paper-like pericarp that grows into a wing-shaped structure.
No nuts in the botanical sense
- Cashew nut , a seed of a false fruit
- Tigernut (Chufa nut), a plant tuber
- Coconut , stone core of a stone fruit
- Kola nut , seeds of a follicle fruit
- Almond , stone core of a stone fruit
- Nutmeg , seeds of a follicle fruit
- Brazil nut (Brazil nut, Juvianuss), hard-shelled seeds from a fruit capsule
- Pecan , stone core of a stone fruit
- Pili nut , stone core of a stone fruit
- Pistachio , stone core of a stone fruit
- Shea nuts , the fruits are botanically speaking berries .
Effects of nuts on health
Nuts stabilize the sugar level, support the blood vessels and reduce the risk of stomach and prostate cancer as well as heart attacks . In a clinical study from 1990, daily consumption of 100 g of almonds after four weeks reduced the blood cholesterol level by twelve percent. Further studies in which smaller amounts or other nuts such as whale, peanut or macadamia nuts were consumed showed comparable effects.
It has not been conclusively clarified which ingredients, in addition to unsaturated fatty acids, have the positive health effects of the nut. Because of the high fat content, one should also consider how the consumption of nuts affects the energy balance .
Whole nuts should be avoided in children under four years of age. Due to their shape and size, these can inadvertently get into the windpipe and cause shortness of breath and even suffocation . Peanuts in particular are dangerous for children because the soft shell can be opened easily. Especially in the run-up to Christmas, there are always shortness of breath from nuts and almonds.
Fat content and calorific values
Food table of the DFL
|Nut fruit||Fat content in g / 100 g||Calorific value in kJ / 100 g||Calorific value in kcal / 100 g|
|Peanut (unsalted, roasted)||49.4||2423||585|
|Hazelnut (without seed shell)||61.6||2662||644|
|Almond (without seed shell)||54.1||2411||583|
|Pistachio (without seed shell)||51.6||2406||581|
|Walnut (without seed shell)||62.5||2738||663|
The nutrients and vital substances listed depend on the type of nut. In their entirety, nuts contain the water-soluble vitamin B1 , which is responsible for the carbohydrate metabolism in the body. Other ingredients are unsaturated fatty acids , high-quality vegetable proteins, fats, easily usable carbohydrates, fiber , sodium, potassium, calcium, phosphorus, niacin , essential amino acids , fluorine, iron, copper, magnesium, various B vitamins and vitamins A , C, D. and E. Furthermore, sugar, linoleic acid , linolenic acid , manganese and folic acid .
Germans consume an average of 3.3 kilograms of nuts per person per year. In 2004, 271,000 tons of nuts were imported to Germany. The main processor is the confectionery industry.
- Reinhard Lieberei, Christoph Reisdorff: Crop science. Founded by Wolfgang Franke , 7th edition. Thieme-Verlag , Stuttgart 2007, ISBN 978-3-13-530407-6 .
- Werner Rauh : Morphology of useful plants. 2nd edition, Quelle & Meyer , Heidelberg 1950, Quelle & Meyer, 1994, ISBN 978-3-494-01228-5 (reprint).
- Horst Bickel, Roman Claus, Roland Frank, Gert Haala, Martin Lüdecke, Günther Wichert, Dirk Zohren: NATURA - biology for high school students. Klett-Verlag , Stuttgart 2002, ISBN 3-12-045200-9 .
- Wolfgang Griepentrog: The root omens of Germanic and their prehistory. Institute for Linguistics of the University of Innsbruck, Innsbruck 1995, ISBN 978-3-85124-651-3 , pp. 471–473.
- The shell proves: The walnut is really a nut at Ruhr-Univ. Bochum, July 21, 2006, accessed on August 6, 2017.
- Nuts in the diet. (PDF; 141 kB) Archived from the original on January 31, 2012 ; Retrieved December 27, 2010 . A report by the Federal Research Center for Nutrition and Food.
- Paediatricians are currently warning at Christmas time: Nuts and almonds are dangerous for children under four years of age at Pediatricians-on-the-Net.
- Risk of suffocation of small children from nuts at the Federal Institute for Risk Assessment (BfR), December 22, 2009.
- German Research Institute for Food Chemistry, Garching (ed.): Food table for practice . The little souci · specialist · herb. 4th edition. Wissenschaftliche Verlagsgesellschaft mbH, Stuttgart 2009, ISBN 978-3-8047-2541-6 , p. 396-406 .